after 3pm, Sydney time (other
locations). The full disk of Venus should be visible
as a tiny black dot on the Sun by 3.30pm and will be partly across
the Sun at sunset. The whole event takes about 6 hours so we in Sydney
will miss more than half of it. :(
Always supervise children who are interested in
this rare event. Never, ever
the sun directly or through an amateur telescope or binoculars
(do not trust a solar filter
equipment - especially
Note that welding goggles and the like are useless because Venus is so small, compared with the Sun's disk. If you have very good eyes and can easily see craters on the Moon unaided then you might be able to spot Venus crossing the Sun. The rest of us will need to use a telescope to project the image (see below) or watch the event on the Internet.
are useless for this event and sunglasses
will not protect the eyes from
One safe way to use a small telescope is
the image onto a screen using a 90 degree mirror (see pictures
below) - then several people can observe the event without fighting
over the telescope. Practice this technique by observing sun spots
before the event - this will also help you distinguish between sunspots
If you can set up in or next to a building (remember the Sun
will be low in the western sky in Sydney) you may be able to project a
much larger image than the one pictured onto a screen (or ceiling) in a
Aim the telescope by observing its shadow - the whole of the white
tube will go
into the shadow of the cowl, when the telescope is pointing at the sun.
adjustment until the image appears in focus on the screen. Do not try
to use the
finderscope - it will damage your eyes!
Unless you are lucky enough to have a motor drive telescope will
you need to adjust the aim of the telescope every few minutes to follow
the Sun as it sets in the Western sky (as well as magnifying the image,
telescopes magnify motion). It is much easier to make the adjustment
before the Sun's image moves out of the field of view.
This is the set up showing the Sun's image projected at right
angles, onto a white screen. The telescope has a 60mm main lens. With
larger telescopes it may be advisable to partly cover the end of the
tube to cut out some of the sun's light.
This shot shows a good observing position. I could easily see some sunspots from here. Note that the finderscope has been removed (or cover it up) - although small it can still easily damage the eye by concentrating the Sun's rays.
Here is another view of the set up. If the surrounds are relatively dark, like this room, then the screen can be moved further away to obtain a larger image.